Summer Program

How to run a summer program

Examples of summer programs are producing monarchs for visitors at a nature center, bringing monarchs to the library for children to see, or for children at a day camp.

Producing monarchs for a summer program is very different from producing eggs for schools.  In the former case, you need just enough eggs to produce sufficient numbers of caterpillars, chrysalids, and adults.  Each caterpillar gets shown many times.  But if you provide eggs for schools, hundreds or thousands of eggs are needed.  You need at least five eggs per class, because most teachers lose a few due to various mishaps, and may even miss the eclosure if it happens before children arrive for class.

The goals... 

• Introduction to the life cycle.  Show alive all stages from egg to adult. Have a life cycle poster on display.  You can also display hatched eggshells, discarded caterpillar skins, and crysalids.
• Hands-on introduction to insects.  Caterpillars are friendly and benign; their skin is soft.  Handling is a good way to combat the fear of insects.
• For kids with sufficient interest or maturity, you can point out various caterpillar behaviors.  These insects have very complex and sophisticated behavior.
• Never miss an opportunity to inform about conservation.  Offer seeds, milkweed plants, or handouts.

Display

The most important things are to decide how you will display the monarch caterpillars, and how many

caterpillars (and display stations) you will need.  For small groups at the library, as few as five caterpillars are probably enough.  

For a display station, I recommend a small table like a card table.  Good lighting is key.  You could provide small flashlights or a goose-necked LED reading light. If you have eggs or small caterpillars, figure out a good way to display using good light and magnification.

Here the butterflies are brightly illuminated with a battery powered LED. The aquarium provides clear view plus "no touch."

Visitors should have an opportunity to handle larger caterpillars and adults.  Large caterpillars are very robust, but supervision is needed, both to encourage handling, and to discourage rare misbehavior.  Kids may try to snatch caterpillars from one another or drop them on the ground.  A few kids may go overboard taking selfies with butterflies.  Remind them that butterflies are sentient beings, not fashion statements.  Caterpillars have lots of interesting behaviors you can point out.

Handling adults is rewarding but you have to deal with possible escape.  They always go to windows or lights.  To recapture, keep a net handy and turn off the lights, so they go to a window where they are easier to recapture.  If you have windows higher than you can reach, that's a problem, because they will fly to the top of the windows. It's somewhat difficult to retrieve adults from large fluorescent tube lights because there are so many nooks and crannies. The best situation is if you have a room where recapture is easy, or if you have a large, walk-in tent of the type used for picnics in mosquito country.  Escape and recapture can be part of the fun.

You can show visitors how to handle adults by letting them climb onto a Q-Tip with honey water (preferred), or by pinching their wings together with your fingers, or by inducing them to climb onto your finger.  Kids can pass a butterfly from one to another by letting them climb from finger to finger.

When a butterfly begins to quiver its wings, that means it is warming up with the intention to fly. When a butterfly turns its head right and left, that means it will fly in about 1-2 seconds--giving you just enough time to put it back in the mesh cube you have nearby.

If you display butterflies in a walk-in tent, and you face the door of the tent away from windows, the sun, or bright light, you have less worry that butterflies will escape (because they are attracted to light).

Caterpillar production and timing

It's likely you can supply your monarch display program by finding eggs and raising them.  In the northern Midwest, Monarchs usually arrive between May 1 and 7.  You can watch their migratory progress on the Journey North website.  Shortly after arrival, they begin laying eggs.  This is the first peak of egg-laying.  Since development from egg to adult takes about a month or longer (depending on temperature), subsequent generations have peaks of egg-laying in June, around July 4, and early August.

Finding eggs

Hunting for eggs makes a great visitor or camp activity.  It shows children what being a hunter-gatherer is all about.  To efficiently find eggs, you need a strategy, along with memory, observation, and keen eyes!  Here are several tricks that enhance your chances:

1. The quickest and surest way to find an egg is to watch for egg-laying behavior of females. Males flit about and chase other males, between nectaring on flowers.  Females also nectar and may be chased by males--but if you see a monarch flitting about milkweeds, or especially descending into the foliage of milkweeds, that's female egg-laying behavior.  It takes only maybe 10 seconds to lay an egg.  Watch and remember where the female disappears from sight in the foliage, then go there to look for an egg.
2. Eggs are laid only on milkweed species (about 15 species in WI).
3. Females almost always lay eggs on the underside of leaves.  So you have to bend plant stems or leaves back to look under.
4. It's more likely that eggs will be laid on the top 1/3 of the plant.
5. It's more likely eggs will be laid on plants along borders--the edge of a prairie, or a lakeshore.
6. A female lays one egg per plant.  This means if you find one egg, it's unlikely there are more.  But if there only a few milkweeds in a good location surrounded by nectar sources, you might find up to 5 eggs on a plant.
7. An individual female has her own egg-laying style.  So, notice where you find eggs, then look in similar places.  For example, if you find an egg on the top of an unfurling leaf, or on the lower part of a plant, then look in similar places.
8. Later in the season when milkweeds get old and crusty, look for eggs on more tender leaves.
9. Search when the sun is strong and low. Good light is especially important for looking at small objects.

When you find an egg, tear off about an inch of leaf containing the egg.  A deli container for leftover food is a good place to carry eggs.  But if you find an egg when you don't have a container, you can carry up to 5 leaves gently and safely pinched between your lips.  When back at your car, you can place them gently in a chest pocket.  Don't leave eggs in the sun or in a hot car.  Since they are tiny, they can overheat quickly.

Raising caterpillars

The most efficient way to raise caterpillars, with the lowest mortality, is the "tabletop method"--indoors (to exclude parasitic tachinid flies) but out in the open.  The caterpillars feed on cut stems of milkweed, the stems placed in water-filled glass jars with metal lids, with a hole cut in the lid just large enough for the stem.  The lids keep caterpillars from falling into the water.  The great advantage of stems with many leaves attached is that the food remains fresh much longer than when you raise them on individual leaves fed water by floral tubes.  In the open, you don't have problems with mildew like you do when you raise caterpillars in a closed container.  But you do need to mist the milkweed stems with caterpillars several times a day. When you use the tabletop method with many caterpillars out in the open, there's a great opportunity to observe caterpillar behavior.

As soon as you get the eggs home, use fine scissors to cut from the leaf a square of milkweed containing the egg, about 1 mm or 1/16-1/8" on a side. With such a small piece of leaf, it can't curl up when dry and trap or hide the caterpillar.  Place one egg in each compartment of a white plastic ice cube tray.  The white plastic makes it easy to see the caterpillars when they emerge.  They hatch 4-5 days after laying. How to observe hatching.  Probably they will just go round and round the rim of the tray. Balance one or more trays on a wine glass standing in a saucer of water.  This keeps predatory spiders out and the caterpillars in.  Check the ice cube tray several times a day for newly emerged caterpillars. When you see one, transfer it with a tiny watercolor brush (or a little triangle of ripped paper towel) to a small, tender tip of milkweed with 4 or 6 leaves standing in a small jar with lid.  If you don't remove newly hatched caterpillars within 12-18 hours, they may rappel down on silk and disappear, or they may cannibalize others.  Mist the ice cube tray several times a day and keep it out of direct sunlight.

Arrange several layers of newsprint on the tabletop, taped together to cover the top, and with the edges turned up (and taped) about 1", to contain the frass.  Place as many jars of water with milkweed stems as you need on the table top--there can be up to 10 large caterpillars on a large milkweed stem.  Source your milkweed using the bin method.  Avoid milkweed from agricultural areas--it may be contaminated with pesticides.  Low levels cause caterpillars to stop eating and become inactive, but not necessarily die.  Link to more about food.

It's very, very important to provide fresh stalks of milkweed for the caterpillars before the old stalks dry out and curl up.  If the leaves curl, you must remove each leaf, uncurl it, and search for caterpillars inside.  After you examine each curled leaf, put it in a wastebasket but don't empty the wastebasket for a day or two.  Probably you missed a few hidden caterpillars. They will climb to the top of the wastebasket by the next day and perhaps crawl around the rim.

When the caterpillars are small, you have to transfer them to fresh food stalks by hand, using the tiny brush.  But after they are about half grown, most will transfer themselves if you lean the old stalks against the new ones.  As the frass accumulates below, vacuum it out with a dust buster or remove the paper and dump it.  If you've constructed the paper carefully, you can probably reuse it.

You can keep as many as 20 jars with milkweed on the top of a card table.  Ten jars with fresh milkweed, plus 10 with stale milkweed that caterpillars are leaving.  Ten fresh stalks with 10 caterpillars each = 100.  You could add more jars if you can fit them.  Just don't have milkweed overhanging the edge (caterpillars might drop to the floor).

The tabletop method somewhat resembles nature, except that in the wild each milkweed seldom supports more than one caterpillar.  Down in the wild foliage, humidity is high because plants transpire and the air is stagnant.  That's why we need to mist eggs, caterpillars, and food plants several times a day.  Some hours after misting, the surface of the milkweed food dries out, preventing mildew.  Cycling of humidity up and down mimics nature (the day-night dew cycle) and prevents disease. More on misting.

We have very few diseased caterpillars using this method.  If you do see diseased or discolored caterpillars, immediately quarantine them.  But remember that caterpillars become inactive for up to 24 hours when they are molting (shedding their skin), so only suspect disease if it is inactive for more than 24 hours.  Other causes of prolonged inactivity are injury, parasitism by tachinid flies, or food contaminated with pesticides.

Transitioning to the chrysalid

When a large caterpillar leaves the food stalk and wanders around the table, especially going round and round the edge, it is probably ready to form the chrysalid.  To make sure, I place him back on a stalk.  But if I soon see him wandering again, he's ready to form the "J."  Also check under the table once a day for caterpillars.

Place these caterpillars in a 32 qt Hefty Hi-Rise bin, with a manilla file-folder covering it, held on loosely with tape.  Mist the inside.  Within about 24 hours, the caterpillars will form a "J", usually hanging from the manilla lid.  If you place some small branches in the bin, they may conveniently make the "J" hanging from these.  Within another 24 hours, they will form the chrysalid.  Mark the manilla next to the "J" with the date of chrysalid formation.  At your convenience you can cut out a small square of manilla containing the chrysalid and attach it to a small bare branch (held upright in a jar) using a pin.  If you have several chrysalids of the same date, attach them to different branchlets of the same branch.  Or you can pin the chrysalids to the roof of a small food tent or mesh cube where they will eventually eclose.  If any caterpillars make their chrysalid on the side of the bin, you need to tease the silk pad (that the chrysalid is attached to) from the plastic using a pin or Exacta knife.  Then the pad can be glued or pinned to a more convenient support.

Chrysalids emerge in 10-11 days (depending on temperature).  Make a list of expected eclosure dates to help plan when you will have emerging butterflies or caterpillars available for showing.   There are ways to delay the timing of hatching or eclosure, to fit these events to your schedule, described elsewhere.

Releasing butterflies

This can be magical.  They need at least 4 hours to dry and firm up their wings.  Temperatures must be above 50 F if sunny, or 60 F if cloudy.  If you release them the day after eclosure, its good (but not essential) to feed them with a Q-tip moistened with a 10% honey solution.  Upon release, notice which direction they fly--often to the SW (especially in the afternoon because the sun is there)--and SW is the migratory direction if you are releasing the migratory generation.  They also usually fly to trees, where they are safe.  They probably spend the night in trees, and rest there during migration.

If you have raised a large number of adults over several days, you can make a big event out of their release.  Place them inside the big mosquito tent (door away from the sun).  People can go inside to feed them or look at them closely.  When you are ready to release them, simply have two people grab the two pillars of the tent on one side, and in one steady motion tip the tent upside down.

I did this once on the SW bike trail in Madison.  Although the event was advertised, many cyclists spontaneously stopped to observe and participate.

Other timing concerns

Each year, it seems harder and harder to find eggs--which puts more and more emphasis on breeding.  Over the summer, you population of captive monarchs will increase, since eggs become easier to find as the summer population builds.  If you learn to breed some of your eclosed butterflies, so much the better.  Finally, having a summer rearing and display program is a good way to get breeding adults so you can provide eggs for schools.

Activities for volunteers

• Finding eggs.
• Transferring eggs to ice cube trays, or tiny caterpillars to milkweed stems.
• Cutting (and perhaps washing) milkweed food.  Use the bin method.
• Transferring caterpillars to fresh food.
• Monitoring for wandering caterpillars ready to "J".
• Cutting, labeling, and preparing chrysalids.
• Monitoring kids who are handling monarchs.
• Feeding captive breeders twice a day, taking notes on butterfly condition and who eats. Most fun!
• Checking for mating pairs, usually in the afternoon or on warm days, taking notes.
• Counting eggs and preparing stalks for delivery to teachers.  This can be time-consuming so you need conscientious volunteers every day when supplying schools.

I underlined jobs that take the most time.  The first, finding food, takes less training.  Some children are much better at these activities than others.  It depends on their temperament and fine motor skills. Some older children may be better at these skills than you are!  It's important to identify talented kids, then find them follow-up activities so they can progress.  You will run across several each season--don't let them down!